﻿<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>IE中屏蔽后退建（Back Space）</title>
    <script type="text/javascript" language="JavaScript">
        
        
    </script>
</head>
<body>
<script type="text/javascript" language="JavaScript">
    document.onkeydown = function (){
        if(event.keyCode === 8){
            if(event.srcElement.tagName.toLowerCase() != "input"
                && event.srcElement.tagName.toLowerCase() != "textarea") //如果是在textarea内
                event.returnValue = false;
        }
    }
</script>

<input type=text><p>
    <textarea cols=80 rows=10></textarea>
</body>
</html>